Japanese Patent No. 2000-344822, filed on Nov. 13, 2000, and Japanese Patent No. 2000-296027, filed on Sep. 27, 2001, are herein incorporated by reference in their entirety.
1. Field of the Invention
The present invention relates to an image display system, image processing method, and program.
2. Description of Related Art
Various color conversion systems such as the color management system (CMS) have been proposed in order to provide uniformity in an image view.
However, the desired image view can differ, depending on individuals and location.
As one example, the standardized method for displaying images in Japan is NTSC, whereas one of the standardized methods for displaying images in Europe is PAL.
A situation that can therefore arise in which an image that was generated on the assumption that it would be viewed as NTSC in Japan is displayed in Europe to Europeans, giving rise to a difference in which the image is viewed, from consideration of the preferences of Europeans.
For that reason, it is not sufficient merely to convert the image information (such as the RGB signals), but it is necessary to convert the image information in accordance with an image characteristic such as the display method selected by the user.
Since an image view is also affected by factors such as ambient light, it is also necessary to detect the visual environment and take that visual environment into consideration when converting the image information.
During the conversion of image information in accordance with the image characteristic and the visual environment, the information used for the conversion must be generated. However, storing conversion information for all assumed image characteristics and visual environments beforehand in a storage region places pressures upon that storage region.
In addition, image information that is generated in real time must be converted in real time.
The present invention was devised in the light of the above-described technical problems and has as an objective thereof the provision of an image display system, image processing method, and program that enable faster reproduction of an optimal image view in accordance with an image characteristic selected by a user.
(1) In order to solve the above described technical problems, according to a first aspect of the present invention, there is provided an image display system which converts image information used for displaying an image and displays the image, based on environmental information obtained by a visual environment detection means which detects visual environment in a display area in which the image is displayed; the image display system comprising:
matrix generation means which generates a conversion matrix used for conversion, based on the environmental information and an image characteristic selected by a user, so as to display the image that is suited to the visual environment and the image characteristic;
matrix conversion means which converts the image information, based on the generated conversion matrix; and
image display means which displays the image based on the converted image information;
wherein the image characteristic is based on at least one of an image display method and an image classification.
(2) According to a second aspect of the present invention, there is provided an image display system which converts image information used for displaying an image and displays the image, based on environmental information obtained by a visual environment detection section which detects visual environment in a display area in which the image is displayed; the image display system comprising:
a matrix generation section which generates a conversion matrix used for conversion, based on the environmental information and an image characteristic selected by a user, so as to display the image that is suited to the visual environment and the image characteristic;
a matrix conversion section which converts the image information, based on the generated conversion matrix; and
an image display section which displays the image based on the converted image information;
wherein the image characteristic is based on at least one of an image display method and an image classification.
(3) According to a third aspect of the present invention, there is provided a computer-readable program for converting image information used for displaying an image, based on environmental information obtained by a visual environment detection means which detects visual environment in a display area in which the image is displayed,
the program causing a computer to function as:
matrix generation means which generates a conversion matrix used for conversion, based on the environmental information and an image characteristic selected by a user, so as to display the image that is suited to the visual environment and the image characteristic; and
matrix conversion means which converts the image information, based on the generated conversion matrix; and
wherein the image characteristic is based on at least one of an image display method and an image classification.
(4) According to a fourth aspect of the present invention, there is provided an image processing method which converts image information used for displaying an image, based on environmental information obtained by a visual environment detection means which detects visual environment in a display area in which the image is displayed, the image processing method comprising:
a matrix generation step of generating a conversion matrix used for conversion, based on the environmental information and an image characteristic selected by a user, so as to display the image that is suited to the visual environment and the image characteristic; and
a matrix conversion step of converting the image information, based on the generated conversion matrix.
The present invention enables conversions that are faster than a case in which a look-up table (hereinafter abbreviated to LUT) is used as conversion information, by generating a conversion matrix for use as conversion information and using that conversion matrix in the conversion of the image information, which also enables a reduction in the dedicated space within a storage region.
It therefore becomes possible to display an image that conforms to the image characteristic selected by the user and the visual environment, in real time.
Note that the image display method in this case refers to a method such as NTSC, PAL, or SECAM. The image classification refers to a system such as RGB or sRGB.
(5) Each of the image display systems may further comprise:
a color gamut calculation means which calculates a target color gamut based on the image characteristic and also calculates a displayable color gamut that is displayable by the image display means in the visual environment, based on the environmental information;
wherein the matrix generation means may generate different conversion matrices according to a relationship between the displayable color gamut and the target gamut, the relationship including a case where the displayable color gamut is larger than the target color gamut, a case where the displayable color gamut is smaller than the target color gamut, a case where the displayable color gamut matches the target color gamut, and a case where the displayable color gamut has a portion that overlaps the target color gamut and a portion that does not overlap the target color gamut.
(6) The program may cause the computer to function as a color gamut calculation means which calculates a target color gamut based on the image characteristic and also calculates a displayable color gamut that is displayable by the image display means in the visual environment, based on the environmental information;
wherein the matrix generation means may generate different conversion matrices according to a relationship between the displayable color gamut and the target gamut, the relationship including a case where the displayable color gamut is larger than the target color gamut, a case where the displayable color gamut is smaller than the target color gamut, a case where the displayable color gamut matches the target color gamut, and a case where the displayable color gamut has a portion that overlaps the target color gamut and a portion that does not overlap the target color gamut.
(7) In the image processing method, the matrix generation step may include a step of calculating a target color gamut based on the image characteristic and also calculating a displayable color gamut that is displayable by the image display means in the visual environment, based on the environmental information; and
the matrix generation step may generate different conversion matrices according to a relationship between the displayable color gamut and the target gamut, the relationship including a case where the displayable color gamut is larger than the target color gamut, a case where the displayable color gamut is smaller than the target color gamut, a case where the displayable color gamut matches the target color gamut, and a case where the displayable color gamut has a portion that overlaps the target color gamut and a portion that does not overlap the target color gamut.
The relationship between a color gamut based on an image characteristic and a color gamut that can be displayed by the image display means depends on the visual environment and the image characteristic. For that reason, it is not possible to reproduce an image appropriately by a method of converting image information that uses only a single conversion matrix.
The present invention makes it possible to reproduce an image more appropriately by dividing the relationships into the above described four patterns and generating a conversion matrix in correspondence to each of those patterns.
(8) In the image display systems and program, the matrix generation means may generate the conversion matrix that emphases either hue reproducibility or color gamut reproducibility, when the displayable color gamut is smaller than the target color gamut or when the displayable color gamut has a portion that overlaps the target color gamut and a portion that does not overlap the target color gamut.
(9) In the image processing method, the matrix generation step may generate the conversion matrix that emphases either hue reproducibility or color gamut reproducibility, when the displayable color gamut is smaller than the target color gamut or when the displayable color gamut has a portion that overlaps the target color gamut and a portion that does not overlap the target color gamut.
This makes it possible to reproduce an image more appropriately, by generating a conversion matrix that emphasizes either hue reproducibility or color gamut reproducibility.
(10) Each of the image display systems may further comprise a projection-type display device having:
the color gamut calculation means;
the matrix generation means;
the matrix conversion means;
the image display means; and
calibration image generation means which generates a calibration image;
wherein the image display means may project the generated calibration image for display on the display area; and
wherein the visual environment detection means may detect the visual environment in the display area in which the calibration image is displayed.
Since this enables generation of a calibration image within the projection-type display device, it makes it possible for the projection-type display device itself to perform calibration, without having to input a calibration image from an external input device such as a PC to the projection-type display device.
(11) The image processing method may further comprise the steps of:
generating a calibration image, prior to compensation of the image information;
displaying the generated calibration image in the display area; and
detecting the visual environment within the display area in which the calibration image is displayed, and generating the environmental information.
This makes it possible to detect the visual environment more appropriately, by using a calibration image. It is therefore possible to reproduce the image view more appropriately.